The cafe was aptly named 'Sunrise' as it's always filled with morning sunlight.

aptly 是形容词 apt（恰当的、贴切的）加上副词后缀 -ly 构成的副词，意思是"恰当地、贴切地"。在句中修饰动词 named，表示咖啡馆的名字取得很合适。